RTC Eclipse Client - Proxy Authentication Error

I am experiencing a proxy authentication error for a customer whilst trying to connect the RTC Eclipse client to a IBM Smart Cloud image. I get the error saying:
CRJAZ1247I The request to the server failed. The server returned the http error 407 with error text "Proxy Authentication Required". Examine any further details here or look at the server log files for more information on how to resolve the issue.
I have tried configuring the Eclipse client for https with the clients proxy server name and port 443 and also added authentication details of the user. This just locks their windows account and doesn't let the client connect to the JTS.
Any ideas would be welcome.
CRJAZ1247I The request to the server failed. The server returned the http error 407 with error text "Proxy Authentication Required". Examine any further details here or look at the server log files for more information on how to resolve the issue.
I have tried configuring the Eclipse client for https with the clients proxy server name and port 443 and also added authentication details of the user. This just locks their windows account and doesn't let the client connect to the JTS.
Any ideas would be welcome.